1. Field of the Invention
The present invention relates to a pointing device, and more particularly, to a pointing device with a detachable roller ball module.
2. Description of the Prior Art
Pointing devices are indispensable PC peripherals. A common prior art pointing device comprises a roller ball, two light gratings, and two sensors within its housing. The light gratings sense rotations of the roller ball in two different directions and the sensors sense rotations of the two light gratings to generate two-dimensional pointing signals. Since the pointing device already can be easily controlled and operated, most of the current focus is on improving its internal structure and modifying the shape of its housing.
Please refer to FIG. 1. FIG. 1 is a perspective view of an internal structure of a prior art pointing device 10. The pointing device 10 comprises a housing 12, and a roller ball module 14 integrally installed in the housing for installing a roller ball (not shown). Because the housing 12 and the roller ball module 14 are integrally built, the roller ball module 14 can not be detached for regular cleaning and maintenance. Moreover, each time a new pointing device is developed, a new mold has to be developed for making the new pointing device. Since a roller ball module has a very complex structure, resigning and making a new mold for the new roller ball module is very costly.